Background: Invasive (IPD, defined as detection of pneumococci in sterile body fluids like meningitis or bacteremic pneumonia) and non-invasive Streptococcus pneumoniae infections (i.e. non-bacteremic pneumonia, otitis media) in adults are associated with substantial morbidity, mortality and costs. In Germany, Pneumococcal polysaccharide vaccination (PPV23) is recommended for all persons >60 years and for defined risk groups (age 5-59). The aim of this model was to estimate the potential cost-effectiveness and benefit-cost ratios of the adult vaccination program (18 years and older), considering the launch of the pneumococcal conjugate vaccine for adults (PCV13).
Methods: A cross-sectional steady state Markov model was developed to estimate the outcomes of PCV13, PPV23 vaccination schemes and 'no vaccination'. Conservative assumptions were made if no data were available for PCV13 and PPV23 respectively. The effectiveness of individual pneumococcal vaccination in adults was adjusted for expected indirect effects due to the vaccination in infants. Data on incidences, effectiveness and costs were derived from scientific literature and publicly available databases. All resources used are indicated. Benefit-cost ratios and cost-effectiveness were evaluated from the perspective of the German Statutory Health Insurance as well as from social perspective.
Results: Under the assumption that PCV13 has a comparable effectiveness to PCV7, a vaccination program with PCV13 revealed the potential to avoid a greater number of yearly cases and deaths in IPD and pneumonia in Germany compared to PPV23. For PCV13, the costs were shown to be overcompensated by monetary savings resulting from reduction in the use of health care services. These results would render the switch from PPV23 to PCV13 as a dominant strategy compared to PPV23 and 'no vaccination'. Given the correctness of the underlying assumptions every Euro spent on the PCV13 vaccination scheme yields savings of 2.09 € (social perspective: 2.16 €) compared to PPV23 and 1.27 € (social perspective: 1.32 €) compared to 'no vaccination', respectively.
Conclusions: Results of the model indicate that the health economic benefit of immunizing adults with PCV13 can be expected to outperform the sole use of PPV23, if the effectiveness of PCV13 is comparable to the effectiveness of PCV7.